The Evolution of Theory
by Street Howitzer
Summary: Sherlock is ever-analytical. Spoilers for PINK, SherlockxJohn slash.


"The Evolution of Theory"

by Street Howitzer

_Subject: Dr. John H. Watson  
>29 January, 2010<em>

He got one look at the man near the door, and a hot little thrill worried along Sherlock's spine. The only outward indication of this reaction was the extra .005 seconds Sherlock took to study him. Back to his experiment, by all appearances, as he mentally catalogued what he'd collected.

_Datum: Regulation haircut, posture of a soldier at ease. Reliant on a cane. Datum: Attended St. Bart's. Datum: Inconsistent tan-line. Wait. He doesn't need that cane._

A man less in control of his faculties would've frowned at this conflict. Sherlock managed to mutter his thanks for the Army doctor's offered cell-phone. In the few seconds it took for him to cross the lab and pluck the cell out of John's hands, Sherlock's brain thrummed, recording every speck of information he could deduce. Each new revelation contradicted the last.

_Datum: Hypervigilance. Datum: Entrusts total stranger with his property. Datum: Living alone, likely in a hotel. Datum: He's got living, immediate relatives who care about his well-being. Datum: Diagnosed with PTSD and a psychosomatic limp, that's got to be it. Datum: Light speckling of oil on his fingertips. Inference: Gun-lubricant._

Sherlock did leave his riding-crop in the mortuary. Lucky, that. It gave him a reason to leave. He wanted to think.

He clipped down the hall, long fingers tightening his scarf. He'd blurted out an invitation for John to move to Baker Street. It was the only way for him to continue observing the doctor. People were predictable; his work depended on human beings reducing their motivations and emotions to simple statistics, the actions of those around him preordained by tables of numbers. And then there was Watson, a healer who'd gone to war, a distrustful, traumatized fellow who gave freely to strangers, an apparently law-abiding citizen who kept an illegal weapon.

_Status: Ongoing._

* * *

><p><em>Subject: Dr. John H. Watson<br>30 January, 2010_

His new flatmate crawled to his bedroom at one-thirty-three, after thanking Sherlock for dinner for the fifth time.

The detective, folded up in his easy chair with a book, nodded a good-night to John. He listened for the upstairs bedroom-door to click, and only waited eight seconds. Sherlock shut his pharmaceutical textbook with a snap, dropped it to the floor, and closed his eyes. He'd gotten his wish-the good doctor'd fetch his few possessions in the morning. Making him available for full-time study. For the first time in some decades, Sherlock questioned if he was up to the task of breaking down a subject.

John confused him.

That was new.

Sherlock's fingers steepled under his chin. Begin at the beginning.

_Subject cannot cope with day-to-day stress, seeks out extraordinary, death-defying stressors. Inference: Counterphobia co-morbid with PTSD. An adrenaline junkie with a constant flow of his drug of choice. Subject displays an over-eagerness to please, and a facile understanding of the law when it contradicts his moral code. Datum: He killed a man tonight, and ate well forty minutes after. Subject is socially adept and has a varied sexual past, yet awkward in conversation, particularly conversations about romance and sex. Inference: self-confident once, but not anymore. No longer enjoys dating or experiences happiness. Conclusion: Typical victim._

His eyebrows drew together. John Watson didn't fit Sherlock's experience with average folk. "Typical" was telling Sherlock to piss off, it was grumbling 'freak' when he passed by or spitting the word in his face, it was seeing his consulting detective work as a stupid hobby, or a voyeuristic outlet for psychopathy. John, on the other hand, was well in the habit of calling Sherlock fantastic. Having known him for all of six hours.

So much more fun than the skull; John scorched his thoughts, honed them into scalpels. A singular whetstone.

_Status: Ongoing._

* * *

><p><em>Subject: Dr. John H. Watson<br>3 March, 2010_

Sherlock shared close quarters with exactly three people in his life, all during his university days; anything he'd learned about living with a flatmate, he'd deleted some time ago. He'd quite forgotten that other people slept longer than three hours at a stretch. When he got a text from Lestrade regarding a bloke he knew in the Lancing department, a bloke handling a bizarre case of suspected child-abuse, Sherlock strode up the stairwell to John's room though he knew it was seven-forty-six in the morning. The detective had woken before dawn. That John could be anything but awake and fully dressed was out of the question.

He threw the door open with a "Get your heavy coat, John, our train leaves for Sussex in an hour-" and stopped.

The doctor sat cross-legged on his bed. He wore shapeless navy pajama-trousers, nothing else. He faced the door as he contorted to rub his own shoulder-blade. An orange-tinged bottle laid perpendicular to John's knee. He jolted, like he'd been caught sneaking a wank. His round face scarleted.

"Right," John said, "an hour. Uh, s-sorry. This is, ah, it's, my shoulder." His arms curled round his waist. Sherlock focused on John's fingers, they were greasy with whatever was in that bottle. He cocked his head and read the label.

_Subject uses Bio Oil to fade his gunshot scar,_ went the buzzing machine of Sherlock's deductive powers. _Subject used to be muscular, has gotten out of shape. Data: maintains a fair build, thicker arms and legs, a bit of a paunch. Conclusion: Subject experiences self-loathing and desires to change his appearance._

The detective's mouth became a sneer. John kept changing on him, forcing him to update his notations every hour, on the hour. It wouldn't do. "Really, John, why waste your time? No one's going to ask to see you shirtless in Lancing."

That must have come out wrong. He saw a mercurial wince crinkle John's face, then transform to a sunny, false smile. "That's one way of looking at it, I guess," John said. "I'll be dressed in ten minutes. Shut the door after you, will you, Sherlock?"

The door closed behind the detective the same instant John said his name. He stood on the uppermost stair for fifty-one seconds. He had writer's cramp of the brain, too many spinning images and descriptions to analyze.

_Subject's desire for approval extends to reassurances of his physical attractiveness. Datum: Deeply hurt when rejected, even when the rejection is in the context of a platonic friendship. Co-dependent. Inference: A bloody hot mess of mental problems._

That was not a professional notation, but Sherlock's thoughts ranged far from the professional. Why couldn't John have finished his pointless ritual a little earlier, or saved it 'til after Sherlock left? He tried to objectively study the mental picture he'd snapped of his flatmate curled up and relaxed on his mussed-up bed; to his disgust, it was impossible.

_Subject is... different._

He'd not bedded anyone since university. And Victor resembled John the way that Anderson resembled Sherlock-the insignificant brain-space he wasted on memories of Victor recalled an upper-crust moron made of money and rugby-built muscle, possessing all the intelligence and dignity of an oyster. John looked nothing like Victor, or Sherlock, for that matter, and thinking of John in conjunction with Victor crossed a few wires in his deductive machine. He envisioned cleaning the Bio Oil from John's hand, then his shoulder-how dare he try and erase something that fascinated Sherlock. He inferred, from previous experience with other scars, how it would feel to dig his teeth into the uneven keloid stretched across John's shoulder-blade. Imagined the startled moan John'd utter, how it'd feel to splay his hands over the curve of John's stomach, and-

Sherlock marched down the stairs to the sitting-room. His ghostly face was a zero of thought and emotion. Mrs. Hudson offered him a cuppa, as she was already in the kitchen. She got one look at him, stammered an "Oh, my", and went on fixing her tea as though Sherlock weren't there.

Smart woman.

_Status: Suspended. Requires self-analysis. Not worth it._

* * *

><p><em>Subject: Domestic behavior (general)<br>13 March, 2010_

John's paradoxes included his sleep-patterns-sometimes snoring for thirteen hours at a time, sometimes living (if one could call it that for a man who needed his sleep) on cat-naps for eight days or longer. On the ninth night the doctor gave up on sleep and joined Sherlock at three a.m. in the sitting-room, Sherlock turned down the volume on the telly and said: "I've got zolpidem."

The doctor should lecture him on keeping an illegal prescription drug when Lestrade had a history of drugs-busts. Granting Sherlock the perfect chance to discuss John's little secret locked in the second drawer of his writing-desk. Instead he laughed, leaning back in his chair as though he wished it were a bed, and said, "You don't wanna see me on zolpidem, Sherlock. I'm a monster."

That slapped the comeback right out of Sherlock's mouth. He stared at the doctor for four entire seconds. Slouched in his chair, too wound up on adrenaline to sleep, too reliant on the high to properly calm down. Sherlock scratched out the original title of this data-set. _Domestic behavior (general) _turned into _Dr. John H. Watson._

_Subject is highly sensitive to hallucinogenic drugs. Datum: Implies that he experiences violent, possibly psychotic behavior on zolpidem. Subject worries about my reaction. Afraid of hurting me. Inference: Concerned with my physical and emotional well-being._

_Status: Reopened._

* * *

><p><em>Subject: Dr. John H. Watson<br>15 March, 2010_

Sherlock searched for an end to his flatmate's limits, some concrete definition to refine his conclusions. Nothing worked. Sherlock acted the narcissistic prick; John accepted the abuse, clearly furious and just as clearly determined to bottle up his frustration. He sorted everything John said into nonsense or stupidity; John frowned, occasionally snarked back, or else stormed out of their flat to return in silence late in the night. Sherlock slipped conflicted, half-insulting compliments into their stream of conversation; John fell silent, smiling or nodding, then changed the topic.

Sherlock drank in that smile when it appeared. John didn't understand him, not a jot. But John knew he didn't get Sherlock, and largely, he welcomed his not-knowing with the patience of a Zen master. That was as near to understanding as he'd ever be.

Sherlock hadn't run out of brain-hoops for the doctor to jump before resorting to more physical tests. He didn't often try to analyze himself, it felt like standing between two mirrors and counting an endless line of repeating faces. He'd no idea why he took John to their favorite Chinese restaurant after a case well-solved, escorted the doctor home, then followed him up to his bedroom to order John out of his cable-knit sweater and jeans. Likely, he did it to see if John'd break his nose.

But his flatmate's eyes went wide, his round face two shades darker than his sweater, and he said: "Turn off the light."

"Why?"

"Please."

Sherlock liked the sound of that enough to grant John's request. He flicked the switch, then locked the bedroom door for good measure.

_Subject remains unreasonably shy and afraid of rejection._

That datum set the detective's teeth on edge; if circumstance hadn't required Sherlock to learn impulse-control as an adolescent, he'd give John a thumping for his idiotic reluctance. He strode through the pitch-dark, lukewarm room, found John's short, shadowed figure just as the sweater crumpled to the floor. He peeled off the doctor's long-sleeved undershirt with a dreamy remoteness that vanished once John was properly shirtless. His fingertips suggested that caressing the bare, soft curve of John's stomach was better than imagined; his ears agreed, reported the deliciously-surprised sigh John breathed over the crook of his neck.

"More," Sherlock said.

John's hands slipped between their bodies, undid his belt. Sherlock heard the hiss of denim, the scrape of the button popping free of its buttonhole, every last separate click of metal teeth as John unzipped. Not quick enough, Sherlock jerked them down and John actually let him, and what moved him to give Sherlock this much power when he didn't trust anyone else?

John provided him with so much data in the next three hours that it would take days to analyze. Sherlock meant to stick with simple touch, just to prove his inference that John felt good; but the doctor's squirming and panting for air all enthralled him. The only word Sherlock spoke during his explorations was "more", and John's response, always, was "yes". Hands were replaced by lips, tongue and teeth, exploring and probing and marking his flatmate, let him go cruising for girls with fading bite-marks on his chest and his thighs. And John cried out, his hips yearning off the mattress, it'd be a crime not to satisfy him when John wanted to be controlled.

Sherlock learned that John's thick legs tangled naturally with his longer limbs. That John had slept with men before, that this was his first go at receiving. That after two minutes and eighteen seconds, the doctor's silly, self-conscious tension loosened and unwound; that John groaning in pleasured surprise got Sherlock high. That John could give in to him fully, reduce Sherlock's awareness of the world to clenching tight heat, and oh he arched his back to counterthrust onto Sherlock's sex and

_Status: Shutting down; power surge. Continue processing after checking for damage._

-end-


End file.
